This. 100% this.I will also echo, so much that I don’t see the point of having backgrounds at all. Frankly custom backgrounds are going to be so much stringer anyway, the base ones are just a trap.
If they are going this route, then simply say:
Background abilities: choose two skills, one language, 50 gp in starting equipment, and one 1st level feat.
Don’t make it a whole big mechanical “thing” when it’s really not anymore